The Methylation Status Of CpG Islands In Promoter Region Of XEDAR Gene In Gastric Cancer Tissues And Adjacent Carcinomatous Tissues

Objective:To study the methylation status of CpG islands in promoter region of XEDAR gene in gastric cancer tissues and adjacent carcinomatous tissues, then further analyse the correlation between gastric cancer and XEDAR gene's methylation status.Methods:Methylation-specific polymerase chain reaction (MSP) was used to detect the methylation status of CpG islands in promoter region of XEDAR gene in 31 gastric cancer tissue samples,30 adjacent carcinomatous tissue samples and 30 control tissue samples. Calculate the methylation rate of CpG islands in promoter region of XEDAR gene in gastric cancer tissue samples, adjacent carcinomatous tissues samples and control tissue samples that outside gastric cancer more than 5cm. The date was analyzed by SPSS 16.0 software and x2 test, compare the methylation rate of XEDAR gene in gastric cancer tissue samples with control tissue samples, adjacent carcinomatous tissue samples with control tissue samples, well-differentiated and middle-differentiated adenocarcinoma group with poorly-differentiated adenocarcinoma group, group of 22 male patients with gastric cancer with group of 9 female patients with gastric cancer, the standard test of significance was a= 0.05, if P< 0.05, the resultes have statistically significant differences.Results:The methylation rate of 31 gastric cancer tissue samples was 96.77% (30/31), of which the complete methylation rate was 12.90% (4/31) and the partly methylation rate was 83.87% (26/31), the unmethylated rate was 3.23% (1/31). The methylation rate of 30 adjacent carcinomatous tissue samples was 93.33% (28/30), of which the complete methylation rate was 6.67% (2/30) and the partly methylation rate was 86.67% (26/30), the unmethylated rate was 6.67% (2/30). The methylation rate of 30 control tissue samples was 86.67% (26/30), the unmethylated rate was 13.33% (4/30). The methylation rate of 7 well-differentiated adenocarcinoma samples was 85.71% (6/7); The methylation rate of 9 middle-differentiated adenocarcinoma samples was 100% (9/9); The methylation rate of 14 poorly-differentiated adenocarcinoma samples was 100%(14/14); The methylation rate of other types of gastric cancer was 100%(1/1). The methylation rate of 22 male patients with gastric cancer was 100% (22/22); The methylation rate of 9 female patients with gastric cancer was 88.89% (8/9). There was no significant difference of CpG islands' methylation rate in XEDAR promoter region between gastric cancer group and control group (P>0.05); there was no significant difference of CpG islands' methylation rate in XEDAR promoter region between adjacent carcinomatous tissue group and control tissue group (P>0.05); there was no significant difference between well-differentiated and middle-differentiated adenocarcinoma sample group and poorly-differentiated adenocarcinoma sample group (P>0.05); there was no significant difference between group of male patients with gastric cancer and group of female patients with gastric cancer (P>0.05).CONCLUSION:â‘ In the gastric cancer tissue samples, the adjacent carcinomatous tissue samples and the control tissue samples, the CpG islands in promoter region of XEDAR gene were hypermethylated;â‘¡There was no significant difference of CpG islands' methylation rate in XEDAR promoter region between gastric cancer tissue group and control tissue group; there was no significant difference of CpG islands'methylation rate in XEDAR promoter region between adjacent carcinomatous tissue group and control group; there was no significant difference between well-differentiated and middle-differentiated adenocarcinoma sample group and poorly-differentiated adenocarcinoma sample group; there was no significant difference between group of male patients with gastric cancer and group of female patients with gastric cancer.â‘¢MSP was a qualitative and sensitive method for detecting of the methylation status of CpG islands in a gene's special site.